From 05d1eeb9ee640f39dac7c7bbe09274d004546122 Mon Sep 17 00:00:00 2001
From: Stephen Gutekanst <stephen@hexops.com>
Date: Fri, 18 Mar 2022 22:42:56 -0700
Subject: [PATCH] gpu: implement basic Buffer .getConstMappedRange,
 .getMappedRange

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
---
 gpu/src/Buffer.zig         | 16 ++++++++++++----
 gpu/src/NativeInstance.zig | 12 ++++++++++++
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/gpu/src/Buffer.zig b/gpu/src/Buffer.zig
index d12d4d80..bc8f253a 100644
--- a/gpu/src/Buffer.zig
+++ b/gpu/src/Buffer.zig
@@ -11,10 +11,8 @@ pub const VTable = struct {
     reference: fn (ptr: *anyopaque) void,
     release: fn (ptr: *anyopaque) void,
     destroy: fn (ptr: *anyopaque) void,
-    // TODO: typed buffer pointer?
-    // WGPU_EXPORT void const * wgpuBufferGetConstMappedRange(WGPUBuffer buffer, size_t offset, size_t size);
-    // TODO: typed buffer pointer?
-    // WGPU_EXPORT void * wgpuBufferGetMappedRange(WGPUBuffer buffer, size_t offset, size_t size);
+    getConstMappedRange: fn (ptr: *anyopaque, offset: usize, size: usize) []const u8,
+    getMappedRange: fn (ptr: *anyopaque, offset: usize, size: usize) []u8,
     setLabel: fn (ptr: *anyopaque, label: [:0]const u8) void,
     mapAsync: fn (
         ptr: *anyopaque,
@@ -38,6 +36,14 @@ pub inline fn destroy(buf: Buffer) void {
     buf.vtable.destroy(buf.ptr);
 }
 
+pub inline fn getConstMappedRange(buf: Buffer, offset: usize, size: usize) []const u8 {
+    return buf.vtable.getConstMappedRange(buf.ptr, offset, size);
+}
+
+pub inline fn getMappedRange(buf: Buffer, offset: usize, size: usize) []u8 {
+    return buf.vtable.getMappedRange(buf.ptr, offset, size);
+}
+
 pub inline fn setLabel(buf: Buffer, label: [:0]const u8) void {
     buf.vtable.setLabel(buf.ptr, label);
 }
@@ -120,6 +126,8 @@ test {
     _ = reference;
     _ = release;
     _ = destroy;
+    _ = getConstMappedRange;
+    _ = getMappedRange;
     _ = setLabel;
     _ = Descriptor;
     _ = BindingType;
diff --git a/gpu/src/NativeInstance.zig b/gpu/src/NativeInstance.zig
index 635127b3..9facd1fe 100644
--- a/gpu/src/NativeInstance.zig
+++ b/gpu/src/NativeInstance.zig
@@ -1700,6 +1700,18 @@ const buffer_vtable = Buffer.VTable{
             c.wgpuBufferRelease(@ptrCast(c.WGPUBuffer, ptr));
         }
     }).release,
+    .getConstMappedRange = (struct {
+        pub fn getConstMappedRange(ptr: *anyopaque, offset: usize, size: usize) []const u8 {
+            const range = c.wgpuBufferGetConstMappedRange(@ptrCast(c.WGPUBuffer, ptr), offset, size);
+            return @ptrCast([*c]const u8, range.?)[0..size];
+        }
+    }).getConstMappedRange,
+    .getMappedRange = (struct {
+        pub fn getMappedRange(ptr: *anyopaque, offset: usize, size: usize) []u8 {
+            const range = c.wgpuBufferGetMappedRange(@ptrCast(c.WGPUBuffer, ptr), offset, size);
+            return @ptrCast([*c]u8, range.?)[0..size];
+        }
+    }).getMappedRange,
     .setLabel = (struct {
         pub fn setLabel(ptr: *anyopaque, label: [:0]const u8) void {
             c.wgpuBufferSetLabel(@ptrCast(c.WGPUBuffer, ptr), label);